1. Field of the Invention
The present invention relates to a positioning method for capturing an image of a product to position the product, a positioning apparatus, a program, and a computer readable recording medium.
2. Description of Related Art
Visual inspection is performed for making a pass/fail determination on a product manufactured in a factory. In the visual inspection, an inspection target is photographed by a camera to acquire an inspection target image. From a standard image obtained by capturing an image of a non-defective product to be a standard for the product, a region is set so as to surround the non-defective product. A feature (standard pattern, etc.) of the non-defective product is extracted from the region, and a candidate similar to this feature is searched in an inspection target image. The visual inspection is then performed on the candidate found by the search. Edge information extracted from the standard image is often used in order to find the candidate (Unexamined Japanese Patent Publication No. 2010-067246).
There may be a large number of candidates similar to the standard pattern in the inspection target image. Some candidates may be simply similar as images, and thus an extracted candidate may not be a target of the visual inspection. Also in an application other than the visual inspection, a candidate may need to be sorted.
There is, for example, a request for sorting a product, easy for robot-picking by a robot hand, out of a plurality of products. For example, a product with an obstacle present therearound and likely to fail in robot-picking is desirably removed from the candidates. Further, in an application where an alignment mark provided on a product is detected to position the product, it is necessary to find a way not to erroneously detect a portion having a similar shape to that of the alignment mark. Accordingly, it is an object of the present invention to accurately position a feature portion desired by a user out of an inspection target image.